The invention relates to a chair arm for an office chair, and more particularly to a chair arm which is height-adjustable and rotatable.
To improve the comfort of office chairs, chair arms thereon often are adjustable so that the position of its arm-supporting top cap can be adjusted to accommodate the specific physical characteristics of each user. In this regard, it is known to provide chair arms which are both height-adjustable to permit adjustment of the vertical height of the top cap, and also rotatable to provide further adjustability.
Examples of chair arms which are height-adjustable and rotatable are disclosed in U.S. Pat. Nos. 4,997,054, 5,599,067, 5,839,786, and 5,931,536. Another example of a height-adjustable and rotatable chair arm is disclosed in U.S. Pat. No. 5,647,638 which is owned by the assignee of the present invention and the disclosure which is incorporated herein in its entirety by reference.
The invention relates to an improved chair arm of this type. Each arm of the inventive arm arrangement includes a rigid upright support post which is connected to a seat assembly of the chair and projects upwardly from a respective side edge thereof. An arm assembly is connected to an upper end of the support post so as to be height-adjustable and rotatable relative thereto.
The arm assembly includes a vertically elongate sleeve which fits onto the upper end of the support post in rotatable engagement therewith such that the sleeve is rotatable relative to the support post about a vertical rotation axis. An arm housing is supported on the sleeve so as to be rotatable therewith, and also is vertically movable relative to the sleeve.
To control rotation, a detent arrangement is defined between opposing surfaces of the sleeve and the support post which arrangement defines multiple discrete stop positions which are angularly spaced apart from each other.
In one embodiment, the detent arrangement includes three predefined stop positions wherein the arm assembly is able to rotate through a 360 degree angular path so that the chair arm can extend forwardly or rearwardly. In a second embodiment, the stop positions extend about the entire 360-degree angular path in 10-degree increments.
In addition to being rotatable in combination with the sleeve, the arm housing also is vertically slidable along the sleeve to provide for height adjustment of the arm assembly. The sleeve includes a plurality of vertically spaced apart notches, while the arm assembly includes a manually-actuatable lock mechanism which engages the notches to maintain the arm assembly at a selected elevation relative to the sleeve. The lock assembly thereby is disengaged to permit raising of the arm housing relative to the sleeve to a desired elevation and then re-engaged with the notches to secure the arm housing at this elevation.
The second embodiment of the invention further includes a mounting bracket which is pivotally connected to the seat assembly. This pivot connection permits the entire chair arm to be pivoted outwardly and inwardly to a desired position whereby the rotatable arm housing of the chair arm permits the top cap to be repositioned so that it is maintained substantially parallel to the respective side edge of the seat assembly.
The chair arm arrangements of the invention thereby have a unique height-adjustable and rotatable arm arrangement which is less complex to assemble.
Other objects and purposes of the invention, and variations thereof, will be apparent upon reading the following specification and inspecting the accompanying drawings.